Originally posted by Just1MoreDave A really practical approach: start with the kit lens or two lens set. Take a lot of photos. When you want another lens, use those photos as a set of data. Figure out what focal length you need by looking at focal lengths you commonly use, or how much you need to crop a photo to get the image you want, or how much more field of view you want to add to a photo.
There are two problems with this approach. First, what focal length one prefers may be dependent on aperture. It's possible, for example, that someone prefers to 28mm over 55mm when they shoot at f5.6, but would prefer 55mm to any focal length if they could shoot at f1.4. Yet if all they have ever used is the kits lens, they won't be in a position to know this. If they want a fast lens, it will be for shooting hand-held in lowlight, not for narrow DOF, which they won't be in a position to fully appreciate.
The other problem arises from the fact that it may not be a good thing, from the perspective of developing one's photographic talent, for a person to be continually using the focal ranges they are most comfortable at. Perhaps the comfort level reflects bad compositional habits reinforced by the versatility and "practicality" of the zoom. Perhaps the comfort level merely reinforces skill at using one specific focal length(s), at the expense of skill using others. If you want to be really good at something, sometimes you have to concentrate more on where you weakest. In basketball, for instance, you may have to practice more with your off-hand, because that's where you're weakest. Perhaps being forced to use focal lengths one is not completely comfortable with is better for the development of one's skill and talent, and will, in the long run, make one into a more well-rounded photographer.
In any case, it was not so very long ago when every photographer started out using primes. In terms of
learning photography, there are real advantages to using primes, as they are better at teaching the benefits of narrow DOF and because, precisely due to their limitations, they force one to really think about composition, rather than settling for the easy, cliche shot.